Posted by jansa on .
1. A random sample of n = 16 scores is selected from a normal distribution with a mean of µ = 50 and a standard deviation of á = 10.
What is the probability that the sample mean will have a value between 45 and 55?
What is the probability that the sample mean will have a value between 48 and 52?
What range of values has a 95% probability of containing the sample mean?
Z = (score-mean)/SEm (Standard Error of the mean)
SEm = SD/√(n-1) (You can use n)
Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportions related to the various Z scores.
95% = mean ± 1.96 SEm